[𝘀𝗽𝗿] changes introduced through rebase

Created using spr 1.3.6-beta.1

[skip ci]

Author: Prabhuk

clang/include/clang/Basic/CodeGenOptions.def

@@ -78,6 +78,8 @@ CODEGENOPT(EnableNoundefAttrs, 1, 0) ///< Enable emitting `noundef` attributes o
 CODEGENOPT(DebugPassManager, 1, 0) ///< Prints debug information for the new
                                    ///< pass manager.
 CODEGENOPT(DisableRedZone    , 1, 0) ///< Set when -mno-red-zone is enabled.
+CODEGENOPT(CallGraphSection, 1, 0) ///< Emit a call graph section into the
+                                   ///< object file.
 CODEGENOPT(EmitCallSiteInfo, 1, 0) ///< Emit call site info only in the case of
                                    ///< '-g' + 'O>0' level.
 CODEGENOPT(IndirectTlsSegRefs, 1, 0) ///< Set when -mno-tls-direct-seg-refs

clang/include/clang/Driver/Options.td

@@ -4291,6 +4291,10 @@ defm data_sections : BoolFOption<"data-sections",
   PosFlag<SetTrue, [], [ClangOption, CC1Option],
           "Place each data in its own section">,
   NegFlag<SetFalse>>;
+defm call_graph_section : BoolFOption<"call-graph-section",
+  CodeGenOpts<"CallGraphSection">, DefaultFalse,
+  PosFlag<SetTrue, [], [CC1Option], "Emit a call graph section">,
+  NegFlag<SetFalse>>;
 defm stack_size_section : BoolFOption<"stack-size-section",
   CodeGenOpts<"StackSizeSection">, DefaultFalse,
   PosFlag<SetTrue, [], [ClangOption, CC1Option],

clang/lib/CodeGen/BackendUtil.cpp

@@ -455,6 +455,7 @@ static bool initTargetOptions(DiagnosticsEngine &Diags,
   Options.StackUsageOutput = CodeGenOpts.StackUsageOutput;
   Options.EmitAddrsig = CodeGenOpts.Addrsig;
   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
+  Options.EmitCallGraphSection = CodeGenOpts.CallGraphSection;
   Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
   Options.EnableAIXExtendedAltivecABI = LangOpts.EnableAIXExtendedAltivecABI;
   Options.XRayFunctionIndex = CodeGenOpts.XRayFunctionIndex;

clang/lib/Driver/ToolChains/Clang.cpp

@@ -6609,6 +6609,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(A->getValue());
   }
 
+  if (Args.hasFlag(options::OPT_fcall_graph_section,
+                   options::OPT_fno_call_graph_section, false))
+    CmdArgs.push_back("-fcall-graph-section");
+
   Args.addOptInFlag(CmdArgs, options::OPT_fstack_size_section,
                     options::OPT_fno_stack_size_section);
 

clang/test/Driver/call-graph-section.c

@@ -0,0 +1,5 @@
+// RUN: %clang -### -S -fcall-graph-section %s 2>&1 | FileCheck --check-prefix=CALL-GRAPH-SECTION %s
+// RUN: %clang -### -S -fcall-graph-section -fno-call-graph-section %s 2>&1 | FileCheck --check-prefix=NO-CALL-GRAPH-SECTION %s
+
+// CALL-GRAPH-SECTION: "-fcall-graph-section"
+// NO-CALL-GRAPH-SECTION-NOT: "-fcall-graph-section"

llvm/include/llvm/CodeGen/AsmPrinter.h

@@ -173,6 +173,32 @@ class AsmPrinter : public MachineFunctionPass {
   /// Emit comments in assembly output if this is true.
   bool VerboseAsm;
 
+  /// Store symbols and type identifiers used to create call graph section
+  /// entries related to a function.
+  struct FunctionInfo {
+    /// Numeric type identifier used in call graph section for indirect calls
+    /// and targets.
+    using CGTypeId = uint64_t;
+
+    /// Enumeration of function kinds, and their mapping to function kind values
+    /// stored in call graph section entries.
+    /// Must match the enum in llvm/tools/llvm-objdump/llvm-objdump.cpp.
+    enum FunctionKind {
+      /// Function cannot be target to indirect calls.
+      NOT_INDIRECT_TARGET = 0,
+
+      /// Function may be target to indirect calls but its type id is unknown.
+      INDIRECT_TARGET_UNKNOWN_TID = 1,
+
+      /// Function may be target to indirect calls and its type id is known.
+      INDIRECT_TARGET_KNOWN_TID = 2,
+    };
+
+    /// Map type identifiers to callsite labels. Labels are only for indirect
+    /// calls and inclusive of all indirect calls of the function.
+    SmallVector<std::pair<CGTypeId, MCSymbol *>> CallSiteLabels;
+  };
+
   /// Output stream for the stack usage file (i.e., .su file).
   std::unique_ptr<raw_fd_ostream> StackUsageStream;
 
@@ -414,6 +440,8 @@ class AsmPrinter : public MachineFunctionPass {
   void emitKCFITrapEntry(const MachineFunction &MF, const MCSymbol *Symbol);
   virtual void emitKCFITypeId(const MachineFunction &MF);
 
+  void emitCallGraphSection(const MachineFunction &MF, FunctionInfo &FuncInfo);
+
   void emitPseudoProbe(const MachineInstr &MI);
 
   void emitRemarksSection(remarks::RemarkStreamer &RS);

llvm/include/llvm/CodeGen/CommandFlags.h

@@ -132,6 +132,8 @@ bool getEnableStackSizeSection();
 
 bool getEnableAddrsig();
 
+bool getEnableCallGraphSection();
+
 bool getEmitCallSiteInfo();
 
 bool getEnableMachineFunctionSplitter();

llvm/include/llvm/CodeGen/MIRYamlMapping.h

@@ -483,6 +483,10 @@ struct CallSiteInfo {
   MachineInstrLoc CallLocation;
   std::vector<ArgRegPair> ArgForwardingRegs;
 
+  /// Numeric callee type identifier used for call graph section.
+  using TypeIdTy = std::optional<uint64_t>;
+  TypeIdTy TypeId;
+
   bool operator==(const CallSiteInfo &Other) const {
     return CallLocation.BlockNum == Other.CallLocation.BlockNum &&
            CallLocation.Offset == Other.CallLocation.Offset;
@@ -511,6 +515,7 @@ template <> struct MappingTraits<CallSiteInfo> {
     YamlIO.mapRequired("offset", CSInfo.CallLocation.Offset);
     YamlIO.mapOptional("fwdArgRegs", CSInfo.ArgForwardingRegs,
                        std::vector<CallSiteInfo::ArgRegPair>());
+    YamlIO.mapOptional("typeId", CSInfo.TypeId);
   }
 
   static const bool flow = true;

llvm/include/llvm/CodeGen/MachineFunction.h

@@ -26,11 +26,14 @@
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
+#include "llvm/IR/Constants.h"
 #include "llvm/IR/EHPersonalities.h"
+#include "llvm/IR/Instructions.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/ArrayRecycler.h"
 #include "llvm/Support/AtomicOrdering.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/MD5.h"
 #include "llvm/Support/Recycler.h"
 #include "llvm/Target/TargetOptions.h"
 #include <bitset>
@@ -486,6 +489,40 @@ class LLVM_ABI MachineFunction {
   struct CallSiteInfo {
     /// Vector of call argument and its forwarding register.
     SmallVector<ArgRegPair, 1> ArgRegPairs;
+
+    /// Callee type id.
+    ConstantInt *TypeId = nullptr;
+
+    CallSiteInfo() = default;
+
+    /// Extracts the numeric type id from the CallBase's type operand bundle,
+    /// and sets TypeId. This is used as type id for the indirect call in the
+    /// call graph section.
+    CallSiteInfo(const CallBase &CB) {
+      // Call graph section needs numeric type id only for indirect calls.
+      if (!CB.isIndirectCall())
+        return;
+
+      std::optional<OperandBundleUse> Opt =
+          CB.getOperandBundle(LLVMContext::OB_type);
+      // Return if the operand bundle for call graph section cannot be found.
+      if (!Opt)
+        return;
+
+      // Get generalized type id string
+      auto OB = *Opt;
+      assert(OB.Inputs.size() == 1 && "invalid input size");
+      auto *OBVal = OB.Inputs.front().get();
+      auto *TypeIdMD = cast<MetadataAsValue>(OBVal)->getMetadata();
+      auto *TypeIdStr = cast<MDString>(TypeIdMD);
+      assert(TypeIdStr->getString().ends_with(".generalized") &&
+             "invalid type identifier");
+
+      // Compute numeric type id from generalized type id string
+      uint64_t TypeIdVal = MD5Hash(TypeIdStr->getString());
+      IntegerType *Int64Ty = Type::getInt64Ty(CB.getContext());
+      TypeId = ConstantInt::get(Int64Ty, TypeIdVal, /*IsSigned=*/false);
+    }
   };
 
 private:

llvm/include/llvm/MC/MCObjectFileInfo.h

@@ -68,6 +68,9 @@ class MCObjectFileInfo {
   /// Language Specific Data Area information is emitted to.
   MCSection *LSDASection = nullptr;
 
+  /// Section containing metadata on call graph.
+  MCSection *CallGraphSection = nullptr;
+
   /// If exception handling is supported by the target and the target can
   /// support a compact representation of the CIE and FDE, this is the section
   /// to emit them into.
@@ -355,6 +358,8 @@ class MCObjectFileInfo {
   MCSection *getFaultMapSection() const { return FaultMapSection; }
   MCSection *getRemarksSection() const { return RemarksSection; }
 
+  MCSection *getCallGraphSection(const MCSection &TextSec) const;
+
   MCSection *getStackSizesSection(const MCSection &TextSec) const;
 
   MCSection *getBBAddrMapSection(const MCSection &TextSec) const;